1. Field of the Invention
This invention relates to a flashlight photographing device having an internal flash device.
2. Description of the Prior Art
A camera having an internal or built-in flash device is already known wherein, when an external flash device is mounted on the camera, emission of flashlight from the internal flash device is inhibited to allow only the external flash device to emit flashlight.
In a conventional camera of the type just mentioned, since emission of flashlight from the internal flash device is inhibited when an external flash device is mounted on the camera, even if the internal flash device has been charged up already, it must be waited that the external flash is charged up. Accordingly, charging of the internal flash device comes to nothing. Besides, a shutter chance may possibly be missed because flashlight cannot be emitted although the internal flash device is already in a charged up condition.
Also a flashlight photographing device is conventionally known which includes a focal plane shutter and can be selectively set to a leading shutter blind synchronization mode or a trailing shutter blind synchronization mode. In particular, trailing shutter blind synchronized photographing is conventionally disclosed, for example, in Japanese Patent Laid-Open No. 56-168480 or Japanese Utility Model Laid-Open No. 63-19832 wherein flashlight is emitted in a synchronized relationship with movement of a trailing shutter blind of a focal plane shutter. Meanwhile, another flashlight photographing device is disclosed, for example, in U.S. Pat. No. 4,717,934 (corresponding to Japanese Patent Laid-Open No. 61-156236) which can be selectively set to a leading shutter blind synchronization mode wherein flashlight is emitted in a synchronized relationship with movement of a leading shutter blind or such a trailing shutter blind synchronization mode as described above. If trailing shutter blind synchronized photographing is performed, then a photograph can be obtained with which it is felt that an object photographed is moving in an appropriate direction. The shutter speed then is determined such that, if a preset shutter speed is higher than a synchronizable speed, then it is set equal to the synchronizable speed, but if the preset shutter speed is slower than the synchronizable speed, then it is set equal to the preset shutter speed.
However, if the trailing shutter blind synchronization mode is selected when an exposure control mode such as a programmed automatic exposure mode or an aperture priority automatic exposure mode is selected wherein a shutter speed is automatically set on the camera side, it is impossible to manually set a shutter speed. Accordingly, a photographing effect by trailing shutter blind synchronized photographing cannot be attained sufficiently.
On the other hand, in a flashlight photographing device of the type including an internal or built-in flash device, charging of the internal flash device is normally performed simultaneously with energization of an automatic focusing motor for driving a focusing lens and/or a film feeding motor for driving a film feeding device by means of a single battery power source.
An exemplary one of flashlight photographing devices of the type mentioned just above is disclosed, for example, in Japanese Utility Model Laid-Open No. 63-128530 wherein, when a flash charging operation of a flash charging circuit is to be performed during operation of a driving circuit such as an automatic focusing motor driving circuit or a film winding motor driving circuit, such flash charging operation is permitted only when the power source voltage is higher than a reference voltage which is set higher than a lowest operable voltage with which the driving circuit can operate. In the flashlight photographing device, when the power source voltage is equal to or higher than the lowest operable voltage of the driving circuit but lower than the reference voltage, no charging operation of the flash charging circuit is performed during operation of the driving circuit.